摘要
为降低梨树枝条修剪装置刀片切割力与切割功耗,该文在自制切割试验台上进行梨树枝条切割试验。采用BoxBenhnken中心组合试验方法对切割试验台的工作参数进行了试验研究,以切割速度、动刀楔角、动刀前角为影响因素,以峰值切割力、切割功耗为目标函数,建立了两者之间的多元数学回归模型。试验结果表明:峰值切割力影响显著顺序依次为动刀楔角、切割速度、动刀前角;切割功耗影响显著顺序依次为切割速度、动刀前角、动刀楔角;最优工作参数组合为切割速度150 mm/min、动刀楔角30°、动刀前角3.5°,对应的峰值切割力和切割功耗分别为2.99 k N、20.54 J,且各性能指标与理论优化值相对误差均小于10%。试验结果可为寻求省力、低功耗的刀片参数提供参考。
The planting area of pear orchard and fruit production in China is at the top in the world, and the pear industry has significant economic position in China. According to scientific plant method,it is sometimes necessary to prune the tree to allow accumulated nutrients in the winter. In recent years, artificial pruning and mechanical pruning are widely used in fruit production, but the late development of orchard cutting device and the relatively low level of mechanization have increased the field management workload. Pear branch belongs to the anisotropy compound material, and it has high-hardness, high-intention. So the selection of cutting technological parameters is very important, and the parementers influenced cutting quality and efficiency. In order to further study the cutting technique, the cutting testbed was designed.The testbed was consisted of a accurate micro-controlled electronic universal testing machine, a self-made cutting device and a vernier caliper. The experimental material was pear branches where 'cuiguan'pear trees were grown, the typical diameter of which is 20 mm. The cutting speed, rotating blade wedge angle and rotating blade rake angle were taken as the influencing factors, and the peak cutting force and power consumption were used as responsive variables in the experimental study. The experiment was designed as a quadratic regression orthogonal of three factors and three levels, and by using the regression analysis method and response surface analysis of the software of Design-Expert 8.0.6, the mathematical model concerning the three factors' impact on the cutting performance was set up and analyzed, and the experimental verification of the mathematical model was also conducted. The results showed that trial factors had great effects, the peak cutting force and power consumption can be fit with quadratic regression polynomial, and P values of the two equations reached to 0.0001 and 0.0009 respectively, and the values showed that models is much better. The coefficients of determination(R2) were 0.9914 and 0.9812 respectively, and the values showed that 98% of the response values can be explained by models. The significant effects of rotating blade wedge angle, cutting speed and rotating blade rake angle reducing the peak cutting force were in a decreasing order. The significant effects of cutting speed, rotating blade rake angle and rotating blade wedge angle on reducing power consumption were in a decreasing order. The best model of the integrated cutting parameters were as follows: when the cutting speed was 150 mm/min, the rotating blade wedge angle was30 ° and rotating blade rake angle was 3.5 °, the peak cutting force and power consumption by the models respectively were2.92 k N and 21.27 J. The model validation tests had been repeated for 3 times on cutting testbed by using the optimization results in the laboratory, the values of max cutting force and power consumption respectively were 2.99 k N and 20.54 J.Both of the relative errors between the experimental and predicted values of max cutting force and power consumption were less than 5%, which indicated a reasonable choice of optimization conditions. These results that the optimization of cutting speed, rotating blade wedge angle, rotating blade rake angle will result in peak cutting force and power consumption saving,and it can provide reference for further study of blade optimization of pear cutting device.
出处
《农业工程学报》
EI
CAS
CSCD
北大核心
2015年第S2期75-82,共8页
Transactions of the Chinese Society of Agricultural Engineering
基金
江苏省农业科技自主创新资金项目(CX(12)3074)
公益性行业(农业)科研专项经费资助项目(201203025)
关键词
机械化
优化
模型
切割装置
梨树枝条
响应曲面
回归分析
mechanization
optimization
models
cutting device
pear branch
response surface methodology
regression analysis
